The invention relates to a coffee machine, in particular a fully automatic coffee machine comprising a water tank, a heating device for heating water, a brewing unit for leaching out ground coffee beans via the water heated in the heating device, a water line system encompassing at least one water line, as well as a feed pump for conveying water out of the water tank through the water line system.
Fully automatic coffee machines are generally known. The latter encompass a water tank, a heating device, a brewing unit along with a feed pump, with which water can be conveyed from the water tank via the heating device and into the brewing unit, in which ground coffee (ground coffee beans) can be leached out with the heated water. The coffee product then exits the brewing unit toward the beverage cup. Most of the time, fully automatic coffee machines also have a coffee bean storage container along with an integral grinder, in which coffee beans can be freshly ground, to then be supplied to the brewing unit prior to a brewing process. Additionally known are fully automatic coffee machines that also exhibit a steam generating unit and/or a milk froth generating unit. Known fully automatic coffee machines must be decalcified and cleaned at regular intervals. In order to decalcify fully automatic coffee machines, it is common practice to add decalcifying agents to the water tank, wherein decalcifying agents are often used in the form of tablets, which according to manufacturer instructions must be suitably dissolved in water before added to the water tank. In practice, however, decalcifying tablets are frequently dissolved in the water container. Given an incorrect dissolution or premature start of the decalcifying process, this in turn causes as yet undissolved decalcifying agent to be conveyed into the water line system, where it can lead to deposits and other disadvantages. In known fully automatic coffee machines, the water tank must be manually cleaned after the decalcifying process, so as to prevent coffee product from becoming contaminated by decalcifying agent after a decalcifying process. In order to clean fully automatic coffee machines, in particular to dissolve grease in the brewing unit, it is known to directly add a cleaning tablet to the brewing unit, which then dissolves in the brewing unit.